Răspuns:
x² - x = 4
x² - x - 4 = 0
[tex]x=\frac{-(-1)+/-\sqrt{(-1)^{2}-4*1*(-4) } }{2*1}\\\\x=\frac{1+/-\sqrt{17} }{2}\\\\x_{1}=\frac{1+\sqrt{17} }{2}\\\\x_{2}=\frac{1-\sqrt{17} }{2}[/tex]